What Are the Main Options for Applying the Multiple-Use Water Services Paradigm? - Rethinking Infrastructure Design for Multi-Use Water Services - page 42

What Are In ltration Trenches?

An in filled with permeable material, such as

rock and gravel, which is used to capture, treat, store and in

ltration trench is an excavation

ltrate storm
water, enhancing the natural capacity of the ground to store and drain.
In ltrate into the soil from the bottom and

sides of the trench. The treatment procedure involves retention of sediments,
nutrients, dissolved heavy metals and other toxic substances. They can be
constructed at open spaces, such as parking lots and streets, as a simple trench
system or combined with other

ltration trenches allow water to in

filtering systems, such as grassed swales and

vegetated filter strips to increase pollution removal.

Main limitations regarding this technique concern the high clogging potential,
the regular maintenance needed to remove retained pollutants and preserve
ef

ciency and the risk of groundwater contamination if soils are coarse.
Source Melbourne water
http://www.melbournewater.com.au/Planning-and-building/Stormwater-
management/

What Are Retention Ponds? Retention ponds can provide both storm water
attenuation and treatment, while supporting emergent and submerged aquatic
vegetation along their shoreline. Run-off is detained in the pool, while the
retention time promotes pollutant removal through sedimentation and bio-
logical uptake mechanisms. Maintenance requires removal of debris and lit-
ter, cleaning of the inlet, sediment removal and vegetation management.
The need for adequate surface may constrain the construction of retention
ponds in highly dense urban areas, while if the in ow is limited (due to the

small number of storm events) and combined with poor maintenance anaer-
obic conditions may occur and consequent health risk.

Source www.susdrain.org